The proposed project will examine the intracellular binding of hydrocortisone to "receptor" molecules of pig hippocampus, hypothalamus and anterior pituitary and the influence of binding of these hormones on specific nuclear effects. The specific aims of the project are: 1. To investigate cytoplasmic and nuclear binding of hydrocortisone and their interrelationships. 2. To study the influence of hormone binding on certain nuclear effects of hydrocortisone (binding to DNA, histone or non-histone proteins and RNA polymerase activity). 3. To determine the effects of various synthetic and non-synthetic steroids - dexamethasone, corticosterone, testosterone, and estradiol on the binding of H3- hydrocortisone to cytoplasmic and nuclear binding proteins. 4. To determine characteristics of the binding molecules in cytosol and nucleus (nature, molecular weight, isoelectric point), the nature of the bond between ligand and receptor molecule (covalent versus ionic, optimum pH, dissociation constant), and the identity of the ligand (hydrocortisone or metabolite). 5. To compare the above phenomena in hypothalamus with that in the hippocampus and anterior pituitary.